48He replied to him, “Who is my mother, and who are my brothers?” 49Pointing to his disciples, he said, “Here are my mother and my brothers. 50For whoever does the will of my Father in heaven is my brother and sister and mother.”
Matthew 12:48-50

For Jesus, discipleship was not a program or a Bible study course. It was a relationship—not just a casual relationship, but the closest relationship imaginable. When Jesus was told that His mother and brothers were looking for Him, He used that encounter to teach an important truth about discipleship, that it should be relational, like a family. These discipleship relationships were not to replace blood family, but they were to function with the same type of love, respect, and trust. Many Bible writers also used family terms to describe discipleship and church relationships.

Paul
In his first letter to the Thessalonians, Paul did not use intimidating ecclesiastical terms to identify to himself. Rather, he refers to himself as a brother several times. He reminds them that he dealt with them as a father deals with his own children. He even says that he and his team were gentle among you like a mother caring for her little children(1 Thessalonians 2:7,9,11). Like Jesus, Paul saw discipleship and church relationships as spiritual family.

James
Even though he really was the brother of Jesus (they had the same mother), he seems to call just about everyone his brother. He writes to brothers who are going through trials, brothers who are in humble circumstances, brothers who talk too much, brothers who show favoritism, brothers who have faith without works, brothers who want to be teachers, brothers with untamed tongues, brothers who slander, brothers who are impatient, brothers who grumble, brothers who swear, brotherswho wander away. To James, discipleship was more like a living room filled with brothers, not a classroom filled with students.

Peter
Even a tough aggressive leader like Peter saw discipleship relationships as spiritual family. He referred to Silas as a faithful brother and to Mark as hisson (1 Peter 4:12, 13).

John
Like James and Peter, John often used the B-word. He said that one of his great joys in life was to know that his children are walking in the truth (3 John 4). These children he speaks of are not his flesh and blood sons and daughters, but spiritual sons and daughters.

Unfortunately, today in the church, even the family terms of endearment such as father and brother have often become dead religious titles. Real discipleship, patterned after the New Testament, will function like a family. This does not mean we must call each other brother and sister, but we must treat each other like brothers and sisters.